JPS6338465Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a magnetic tape cassette in which a separate sheet is interposed between the magnetic tape winding layer and the case body.

Conventionally, vinyl chloride, polyester,
Graphite Teflon (product name of DuPont)
A magnetic tape cassette (hereinafter simply referred to as a cassette) in which a separate sheet (hereinafter simply referred to as a sheet) made of a composite of a synthetic resin and a lubricant is interposed is known. In such a cassette, if the sheet is opaque, a portion of the case body corresponding to the tape monitoring window hole must be cut out. Furthermore, even when a translucent sheet is used, scratches may occur due to the tape wrapping layer coming into contact with the portion of the sheet corresponding to the window hole, and these scratches may deteriorate the translucency or change the appearance. For reasons such as deterioration and halving the commercial value, it is common to punch out the portions of the sheet that correspond to the window holes. Incidentally, performing such a punching process not only increases costs but also wastes expensive materials, which is not preferable from the viewpoint of economy and resource conservation.

In addition, in conventional cassettes, the seat is not completely fixed inside the case body, and is only locked with play in an appropriate locking part.
Furthermore, the tape winding layer also has looseness in the width direction of the tape (thickness direction of the case body) within the case body.
The sheet alone cannot hold the tape-wrapped layer sufficiently;
This may cause uneven winding of the tape, deflection of the wound layer, etc., and the running properties of the tape, especially the uniformity of the phase characteristics between the A side and the B side, and the stability of the azimuth, are deteriorated.
When the tape is running at high speeds such as fast forwarding or rewinding, the tape winding layer may rattle, producing high rotational noise, and the relative position between the sheet and the case body or the tape winding layer is not always constant, so each part of the sheet A substantially uniform elastic effect cannot be expected.

On the other hand, an injection molded plate made of a translucent material or a translucent film sheet cut into a predetermined size and shape is fitted into the window hole of the case body, and high-frequency welding, etc. It is fixed by an appropriate method. By the way, in the case of using such an injection molded plate, its light transmittance is inferior to that of a case using a transparent film sheet material, and there is distortion throughout, so that the tape-wrapped layer is clearly visible. However, there were disadvantages in that it was not possible to do so, and the cost was high. In addition, those using a translucent film material have problems such as requiring cutting and poor workability when attaching to the window hole.

In order to eliminate the above-mentioned problems, the present invention provides a magnetic tape cassette in which highly lubricating and translucent separate sheets are interposed between the upper and lower surfaces of the magnetic tape winding layer and the upper and lower surfaces of the case body. The separate sheet has a part that fits into the tape monitoring window hole with its substantially central part protruding toward one side, and the separate sheet has a part that fits into the tape monitoring window hole so that the main body of the separate sheet floats slightly above the upper and lower surfaces inside the case body. The mating part is fitted into and fixed to the window hole, and a support part for supporting the outer peripheral edge of the main body is provided protruding from the upper and lower surfaces of the case body, and will be described in detail below with reference to the drawings.

The drawing shows one embodiment of the present invention, and numeral 1 denotes a case body formed by connecting upper and lower cassette halves 1a and 1b to each other with screws 2. The front surface of the case body 1 is provided with an opening 3 for inserting a recording/reproducing head of a player, etc., and a pair of insertion holes 4 for a winding shaft are provided at approximately the center of the upper and lower surfaces of the case body 1 so as to pass vertically through the opening 3.
A tape monitoring window 5 is provided so as to be located between each insertion hole 4. Inside the case body 1, a pair of reel hubs 7 around which a tape 6 is wound are rotatably supported by the inner peripheral protrusion 4a of the insertion hole 4. This tape 6 is sent out from one reel hub 7, guided by a guide roller 8 and a guide protrusion 9, passes inside the opening 3, and is wound onto the other reel hub 7. This reel hub 7
A highly lubricating and translucent sheet 10 is inserted between the upper and lower surfaces of the wound portion of the tape 6 (hereinafter both are collectively referred to as the magnetic tape wound layer) and the upper and lower surfaces inside the case body 1. be done.

This sheet 10 is made of a composite of a synthetic resin such as vinyl chloride or polyester and a lubricant, and as shown in FIG.
The four corners of 10b, 10c, and 10d are removed, and a through hole 10e for inserting the inner circumferential edge 4a of the insertion hole 4 is bored approximately in the center.
In the middle of e is a window hole 5 on the upper or lower surface of the case body 1.
A fitting portion 10f is formed by partially protruding the sheet 10 in the direction of the window hole 5 so that the sheet 10 can be fitted into the window hole 5. The main body of each sheet 10 is a case body 1.
The fitting part 10 is slightly raised from the upper or lower surface.
f is fitted into each corresponding window hole 5 from the inside, and at least a portion thereof is fixed to the inner peripheral edge of the window hole 5 by a suitable method such as high frequency welding.
12 is the outer peripheral edge portion 10a to 10d of the sheet 10
Support parts, such as rib parts, which support the case body 1 in the above-mentioned floating state are protrudingly provided at corresponding positions on the upper and lower surfaces of the case body 1. Therefore, the main body of the sheet 10 is always in a state slightly floating above the upper and lower surfaces of the case body 1, which allows the tape-wrapped layer to be held elastically within the case body 1, and the fit of the sheet 10 There is no problem even if the joint portion 10f is fixed.

In addition, 10g is the notch provided in the sheet 10,
The protrusions 11 planted on the upper and lower surfaces of the case body 1 fit together. This notch 10g is unnecessary if the protrusion 11 does not exist on the case body 1.

In this way, the fitting portion 10f of the sheet 10 is fitted and fixed in the window hole 5 such that the main body of the sheet 10 is slightly raised above the upper and lower surfaces of the case body 1, and
By supporting the outer peripheral edges 10a to 10d of the seat 10 in the floating state by the rib portions 12 provided on the case body 1, the seat 10 can move in the horizontal direction while maintaining a substantially uniform elastic effect in each part. Since this can be completely prevented, the tape winding layer rotates smoothly and orderly, and it is possible to reliably prevent the occurrence of irregular winding of the tape and deflection of the tape winding layer. Therefore, side A, B
This not only improves the uniformity of the phase characteristics of the surface and the stability of the azimuth, but also prevents the occurrence of high rotational noise due to rattling of the tape winding layer during high-speed running of the tape, such as fast forwarding or rewinding. Furthermore, since the outer peripheral edge portions 10a to 10d of the sheet 10 are floated and supported by the rib portion 12, there is less variation in quality compared to the case where such support means is provided on a portion of the sheet 10.

As explained above, according to the present invention, in a magnetic tape cassette in which a highly lubricating and translucent separate sheet is interposed between the upper and lower surfaces of the magnetic tape winding layer and the upper and lower surfaces of the case body, the separate sheet is is formed by protruding its approximately central part to one side,
It has a fitting part to the tape monitoring window hole, and the fitting part is fitted and fixed to the window hole so that the main body of the separate sheet floats slightly above the upper and lower surfaces inside the case body, and the main body Since the support parts that support the outer periphery are provided protruding from the upper and lower surfaces of the case body, there is no need to provide a separate cover for the window hole or to cut out the part corresponding to the window hole from the separate sheet, which saves money. Not only can resources be saved, but since the separate sheet is fixed to the case body, it is easy to incorporate the magnetic tape winding layer into the case body, and the separate sheet is slightly raised from the upper and lower surfaces of the case body. Since the central part is fixed and the outer periphery is supported, an almost uniform elastic effect can be obtained in each part, and it is possible to reliably prevent the occurrence of irregular winding of the tape and deflection of the tape winding layer. It is possible to improve the phase characteristics and azimuth stability of the B side, and also to prevent the occurrence of high rotational noise due to rattling of the tape winding layer during high-speed running of the tape, such as fast forwarding or rewinding. Furthermore, since the outer peripheral edge of the sheet is floated and supported by the rib section, costs can be lowered and quality variations can be reduced compared to when a part of the sheet is provided with a means to float it. There are advantages such as

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is a perspective view of a magnetic tape cassette according to the invention, and Fig. 2 is a perspective view of the magnetic tape cassette with the upper cassette half removed and the tape winding layer section shown in imaginary lines. FIG. 3 is an enlarged cross-sectional view of a portion of the magnetic tape cassette in the direction of the arrow in FIG. 2, and FIG. 4 is an enlarged perspective view of the separate sheet. 1...Case body, 5...Window hole, 6...Tape,
7... Reel hub, 10... Separate sheet,
10a to 10d...outer peripheral edge portion, 10f...fitting portion, 12...supporting portion.

Claims (1)

[Scope of utility model registration request] In a magnetic tape cassette in which a highly lubricating and translucent separate sheet is interposed between the upper and lower surfaces of the magnetic tape winding layer and the upper and lower surfaces within the case body, the separate sheet has a substantially central portion thereof protruding toward one side. the said separate sheet has a fitting part for the tape monitoring window hole, and the fitting part is fitted and fixed to the window hole so that the main body of the separate sheet slightly floats above the upper and lower surfaces inside the case body, A magnetic tape cassette characterized in that a support portion for supporting the outer peripheral edge of the main body is provided protruding from the upper and lower surfaces of the case body.